netfilter: ip6t_{hbh,dst}: Rejects not-strict mode on rule insertion

The current code ignores rules for internal options in HBH/DST options
header in packet processing if 'Not strict' mode is specified (which is not
implemented). Clearly it is not expected by user.

Kernel should reject HBH/DST rule insertion with 'Not strict' mode
in the first place.

Signed-off-by: Yasuyuki Kozakai <yasuyuki.kozakai@toshiba.co.jp>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>